Halogen HPX lamp provides light output for true tissue color and consistent, long-lasting illumination. Coaxial optics produce a shadow-free spot, easier entry into undilated pupils, and a larger field of view. 18 aperture/filter combinations for greater versatility: micro, small, and large spot sizes, cobalt blue filter for corneal exams, fixation target, or slit aperture can be combined with red-free filter, polarizing filter, or unfiltered Halogen HPX illumination. 68 lenses in single-diopter steps for precise resolution (+38 to -30). Sealed optics keep out dust and dirt for years of maintenance-free operation. Rubber brow rest prevents scratching of eyeglasses.